You can do a lot even with the small board space allowed in the freeware version.

If you find you're in need of more space, you can always use a dual-row header, and link to another board via a ribbon cable connector. If you do that, I suggest alternating signal/ground/signal etc. to avoid crosstalk.

In the freeware version, you'd have to split up your schematic into different files. The registered version supports multiple pages for schematics, but not the freeware version.